Methods to produce precisely controlled concentrations of chemical warfare (CW) agents and toxic industrial chemicals, or any chemical vapors using control streams of air, nitrogen, and other carriers are crucial for evaluating the performance of systems and equipment used to protect military combatants or civilians who might be exposed to environments containing these materials. Examples of protective equipment that rely on these methods include chemical vapor filtration and detection systems. Chemical vapor generator systems have been used in the art for calibrating and testing the agent sensitivity of such chemical devices and monitors. A number of methods have been developed for performing such tests and calibrations.
The ability to generate stable vapor concentrations of target analytes has been developed with various techniques to test detection devices within the laboratory environment. Several well-known methods of vapor generation are carried out by using direct contact of the chemical with a carrier gas stream. These include sparging, syringe injection of the liquid material directly into a carrier gas flow stream, and vapor saturation. “Indirect” methods, where a barrier is introduced between the chemical and its vapor, such as permeation, diffusion, and effusion have also been used.